Overview

LISA component is part of RDK DAC framework on STB. Its role is to retrieve, store and maintain DAC bundles and local applications' metadata. LISA is keeping track of what packages are available locally and managing the local storage, both for downloadable bundles as well as persistent storage for the applications. LISA is an abbreviation from Local Inventory & Storage Manager of DAC Apps and it offers an API for a controlling app - typically the operator resident app - to trigger download/install, removal of DAC Apps from that storage.

Lisa is implemented as Thunder out-of-process plugin.  Can be run in a separate container

Relation to RDK Packager

LISA is an alternative to the Packager Thunder Plugin used to retrieve ipkg packages, see https://github.com/rdkcentral/rdkservices/blob/master/Packager/doc/PackagerPlugin.md   

Comparison of LISA with RDK Packager API 

Demo video

DEMO video of e2e DAC flow. You can see actions from LISA in log screen most below.

https://drive.google.com/file/d/11QXXM9WBg8Sw76Eikg5FyodrpIfoBnkL/view

DAC_AWC_LISA.mp4 drive.google.com

Example consuming application

The refapp "resident App" that comes with RDK reference image  uses lisa for downloading DAC bundles. It is a consumer of LISA api.

Here are pointers to its code on where/how it uses LISA 

https://github.com/LibertyGlobal/refapp/search?q=LISA

Demo video of that refapp in action, using LISA to download/store the Youtube/Cobalt DAC-Rialto app and run it

https://drive.google.com/file/d/1ipINJ-LlZBYEJvRUugoruaYO2sjQiraO/view

Data Types

LISA is able to handle the following data:

1. Application-specific:
   • Mandatory application metadata (type, id, version, source URL, name, category)
     • setting on installation request
     • getting
   • DAC bundles
     • downloading
     • deleting
   • Generic resources (files, e.g. icons)
     • downloading,
     • deleting
   • Auxiliary application metadata, dedicated API for:
     • setting
     • updating
     • getting
   • Persistent storage for application
     • creating
     • resetting
     • deleting
   • Storage/persistent storage usage checking
     • getting
2. Global
   • Storage usage checking
     • getting

Sources

current git repo location : https://github.com/stagingrdkm/LISA

TO DO : intention is to move over to github/rdkcentral/LISA in near future

Yocto recipe location : https://code.rdkcentral.com/r/plugins/gitiles/components/generic/rdk-oe/meta-cmf-video/+/refs/heads/rdk-next/recipes-extended/rdkservices/rdkservice-lisa.bb

License : Apachev2

API

Formal definition

Before implementation, at the design stage, the following API in json schema has been defined LISA API .

In later design phase additional lock/unlock api allowing external application manager to signal LISA that a specific app from LISA database is in active use by End user and hence should not be deleted/upgraded at this moment, see description in  LISA API Extension (Locking mechanism)#APISchema

Actual Thunder interface definition/api in defined in dual COM RPC / JSON- RPC interface in https://github.com/rdkcentral/ThunderInterfaces/blob/R2/interfaces/ILISA.h with annotations to automatically autogenerate* the JSON RPC api at build time

Below is description of expected api behaviour in expected use cases.

Overview

API to be exposed in JSON-RPC over WebSocket 

Generic format (see with https://www.jsonrpc.org/specification and https://github.com/rdkcentral/rdkservices/blob/master/SystemServices/README.md):

{"jsonrpc":"2.0","id":{id},"method":"com.lgi.dac.lisa.1.methodName", "params":{payload}}

{id} - An identifier established by the Client that MUST contain a String, Number, or NULL value if included. If it is not included it is assumed to be a notification.

{payload} - A Structured value that holds the parameter values to be used during the invocation of the method. This member MAY be omitted.

Methods

• install 

Download the application bundle tarball from the given URL, unpack files to dedicated directory, create the db entries and persistent storage on success. Asynchronous operation, handle should be used for tracking the request. The id of an app is unique within the database. That means only one kind of (mime)type can be combined and saved with a specific app id.

Request payload: {"type":"application/vnd.rdk-app.dac.native", "id":"<string>", "version":"<string>", "url":"<string>", "appName":"<string>", "category":"<string>"}

Result payload: {"handle":"<string>"}

• uninstall

Uninstall the application: remove application files and - optionally - persistent storage and db entry. Non-blocking operation, handle should be used for tracking the request.

Request payload: {"type":"application/vnd.rdk-app.dac.native", "id":"<string>", "version":"<string>", "uninstallType":"<string>"}

Result payload: {"handle":"<string>"}

• download

Download arbitrary application's resource, e.g. icon. Resource are stored per application id/version. Asynchronous operation, handle should be used for tracking the request. If the resource of given resKey already exists it is replaced by the newly downloaded resource. If the resKey is unique, but the requested resource file already exists on the filesystem, the file should be stored under a different, unique filename, created by appending a suffix to the existing filename.

Request payload: {"type":"application/vnd.rdk-app.dac.native", "id":"<string>", "version":"<string>", "resKey":"<string>", "url":"<string>"}

Result payload: {"handle":"<string>"}

• reset

Deletes the content of the database and/or persistent storage and/or all resources for the application. Synchronous operation, returns response on success or failure. Optional parameters type, id, version are used to filter the applications on which the reset will be performed. If they are not given, the reset operation affects all the data. Synchronous operation, returns a response on success or failure. 

Request payload: {"type":"application/vnd.rdk-app.dac.native", "id":"<string>", "version":"<string>", "resetType":"<string>"}

Response payload: {"status":"<string>"}

• getStorageDetails

Returns information on the storage usage. Depending on provided parameters: overall storage usage, application id storage or application id/version storage. Synchronous operation, returns a response on success or failure. Notes on implementation:

• overall storage usage (for all apps) may be cached based on the data gathered in Initialization and Maintenance flows (see below), however, if returned value is not cached from Initialization and Maintenance flows, the actual value (including current size of the temporary storage) should be returned
• per app and per app/version storage usage should be estimated synchronously on the invocation of the method, temporary storage should not be included
• quota returned in storagePayload is an optional parameter, it is returned only when known to LISA.

Request payload: {"type":"application/vnd.rdk-app.dac.native", "id":"<string>", "version":"<string>"}

Result payload: {"storage":"<storagePayload>"}

• getList

Returns a list of installed applications filtered using optional filtering criteria: type, id, version, appName, category. Synchronous operation, returns a response on success or failure.

Request payload: {"type":"application/vnd.rdk-app.dac.native", "id":"<string>", "version":"<string>","appName":"<string>","category":"<string>"}

Resultpayload: {"apps":"<appsPayload>"}

• setAuxMetadata

Set an arbitrary key: value metadata for a given application. The existing metadata object is replaced (overwritten) by the provided object. Synchronous operation, returns a response on success or failure. 

Request payload: {"type":"application/vnd.rdk-app.dac.native", "id":"<string>", "version":"<string>","auxMetadata":<auxMetadataPayload>}

Result payload: {}

• getMetadata

Get all metadata stored for given application version. Synchronous operation, returns a response on success or failure. 

Request payload: {"type":"application/vnd.rdk-app.dac.native", "id":"<string>", "version":"<string>"}

Response payload: {"status":"<string>","metadata":}

• cancel

Cancel previous asynchronous request.

Request payload: {"handle":"<string>"}

Response payload: {"status":"<string>"}

• getProgress

Get estimated progress of an asynchronous operation.

Request payload: {"handle":"<string>"}

Response payload: {"status":"<string>", "progress":<number>}

Events

• operationStatus

Notification sent on the completion of asynchronous operation.

payload: {"handle":"<string>", "status":"<string>", "details":"<string>"}

Download progress tracking

Tracking of the download progress is implemented using:

• requesting for Content-Length HTTP header before actual transfer, to check for available space and to store the size of the resource
• updating the counter of downloaded bytes on the successful transfer of each data chunk (see libcurl CURLOPT_WRITEFUNCTION)
• returning the updated value of progress parameter on invocation of getProgress API.

Block diagram

Logical modules

LISA auth module

API to be implemented by the library:

• getAuthenticationMethod(appType, id, URL); returned value should indicate one of method:
  • NONE
  • BASIC_AUTH
  • API_KEY_IN_REQUEST
  • API_KEY_IN_HEADER
  • API_KEY_IN_COOKIE
  • CLIENT_CERT
  • BEARER_TOKEN (Oauth2)
• getAPIKey(appType, id, URL, *key, bufferSize); value returned in key buffer contains API key to be included to the request; returns 0 on success, 1 on error (buffer too small), 2 on other errors
• getCredentials(appType, id, URL, *user, *password, bufferSize); returns user/apssword; returns 0 on success, 1 on error (buffer too small), 2 on other errors
• getClientCertsFile(appType, id, URL, *privKeyFileName, *privKeyPassphrase, *clientCertFileName, bufferSize); returns certificate file names; returns 0 on success, 1 on error (buffer too small), 2 on other errors
• getToken(appType, id, URL, *token, bufferSize); returns bearer token; returns 0 on success, 1 on error (buffer too small), 2 on other errors

Metadata

JSON metadata data model

sqlite schema

Note:

The 2 tables in the db schema (apps and installed_apps) are required to be able to correctly handle the case when the application is uninstalled, deleted because of corruption, deleted because of storage capacity issue, or not installed locally (launched from the cloud) but operator or user wants to keep persistent storage of given application intact (for later usage). In this case, an entry in apps table keeps tracking the persistent storage without introducing any other dirty hacks. This approach will also be useful for managing remote applications, for which we don't need to maintain the application's locally downloaded files, but persistent storage might be needed.

-- enable support for foreign keys, available since sqlite version 3.6.19 (2009-10-14)
PRAGMA foreign_keys = ON;

-- table for application ids and persistent storage
CREATE TABLE IF NOT EXISTS apps(
idx INTEGER PRIMARY KEY, -- unique index for the application type/id
type TEXT NOT NULL, -- MIME type 
app_id TEXT UNIQUE NOT NULL, -- unique id of app within given MIME type
data_path TEXT, -- path to app peristent storage, relative to [APPS_STORAGE]/{epoch}
created TEXT NOT NULL -- unix epoch timestamp of when the application entry was created 
);

-- table for installed applications in specific versions
CREATE TABLE IF NOT EXISTS installed_apps (
idx INTEGER PRIMARY KEY, -- unique index for the application type/id/version
app_idx INTEGER NOT NULL, -- reference to apps table, index of the application type/id
version TEXT NOT NULL, -- version of the application
name TEXT NOT NULL, -- name of the application
category TEXT, -- category
url TEXT, -- URL from which the application was downloaded
app_path TEXT, -- path to app files, realtive to [APPS]/{epoch}
created TEXT NOT NULL, -- unix epoch timestamp of when the application was installed
resources TEXT, -- json object with downloaded resources metadata
metadata TEXT, -- json object with auxiliary resources metadata
FOREIGN KEY(app_idx) REFERENCES apps(idx),
UNIQUE(app_idx, version)
);

sqlite quick startup 

1. print tables
SELECT sql FROM sqlite_master WHERE name = 'apps';
SELECT sql FROM sqlite_master WHERE name = 'installed_apps';

2. insert app id
INSERT INTO apps VALUES(NULL, 'application/vnd.rdk-app.dac.native', 'com.lgi.app3', 'dac.native/com.lgi.app3/data', strftime('%s','now'));

3. get app_id of given app
SELECT idx,type,app_id FROM apps WHERE type = 'application/vnd.rdk-app.dac.native' AND app_id = 'com.lgi.app3';

4. insert new application version
INSERT INTO installed_apps VALUES(NULL, <app_idx>, '1.0.0', 'Super-app', 'Game', 'http://download.com/bundle1.tgz', 'dac.native/com.lgi.app3/1.0.0/app', strftime('%s','now'), NULL, NULL, NULL);

5. SELECT app version
SELECT DISTINCT apps.type,apps.app_id,installed_apps.version,installed_apps.metadata FROM installed_apps,apps WHERE apps.type='application/vnd.rdk-app.dac.native' AND apps.app_id='com.lgi.app3' AND installed_apps.version="1.0.0";

6. set meatdata for given app/version
SELECT DISTINCT installed_apps.idx,installed_apps.metadata FROM installed_apps,apps WHERE apps.type='application/vnd.rdk-app.dac.native' AND apps.app_id='com.lgi.app3' AND installed_apps.version="1.0.0";
UPDATE installed_apps SET metadata = '{[{"description","New nice application."},{"parental":"5"}]}' WHERE idx=<idx>;

Storages for data

The logical storages: [APPS] and [APPS_STORAGE] should be defined per platform, to use concrete physical storages.

Epoch

Epoch indicator {epoch} is used for easy invalidation of not supported or revoked format of apps on fundamental changes. May also be used for the antirollback (db authentication - TBD?)

Application files: [APPS]

Apps files are stored in [APPS] storage. 

Paths:

• App's files: [APPS]/dac/images/{epoch}/{id}/{version}/
• App's auxiliary resources (e.g. icons), currently not implemented: [APPS]/dac/images/{epoch}{id}/{version}/res
• LISA's db:  [APPS]/dac/db/{epoch}/apps.db
• Temporary files storage (for downloaded files before unpacking), referred as [APPS_TMP]: 
  • [APPS_TMP] is located in [APPS]/dac/images/tmp
  • [APPS_TMP]/{id}/{version}/ - used for downloading application of given id and given version

Application persistent storage: [APPS_STORAGE]

Apps persistent storage is located in [APPS_STORAGE]. 

Paths:

Apps' persistent storage: [APPS_STORAGE]/dac/{epoch}/{id}/

LISA operations

Initialization

Maintenance and Cleanup

Install

Uninstall

Download

LISA implementation

LISA should be implemented as a Thunder plugin.

An implementation may be based on the Packager code.

Lisa Thunder plugin configuration

{
	"$schema": "plugin.schema.json",
    "jsonrpc":"2.0",
	"info": {
		"title": "Local Inventory & Storage Manager of DAC Apps (LISA) Plugin",
        "class": "Lisa",
		"callsign": "org.rdk.dac.lisa",
		"locator": "libWPEFrameworkLisa.so",
		"status": "alpha",
		"autostart": true,
		"description": "The Local Inventory & Storage Manager of DAC Apps (LISA) plugin allows authenticated downloading and management of DAC bundles from a remote server. It also manages the persistent storage of the DAC applications.",
		"version": "1.0"
	},
	"interface": {
		"$ref": "{interfacedir}/lisa.json#"
	},
	"configuration": {
		"type": "object",
		"properties": {
			"configuration": {
				"type": "object",
				"properties": {
					"network": {
						"type": "object",
						"required": [
							"timeout",
							"default_retryIn"
						],
						"properties": {
							"timeout": {
								"type": "number",
								"description": "Single resource downloading timeout in seconds"
							},
							"default_retryIn": {
								"type": "number",
								"description": "Default value of GET retry delay in seconds on HTTP/202, when no "Retry-After" header field is returned in the response."
							}
						}
					},
					"storages": {
						"type": "object",
						"required": [
							"apps",
							"apps_storage",
							"apps_tmp"
						],
						"properties": {
							"apps": {
								"type": "string",
								"description": "Path to the persistent storage for downloaded applications top dir"
							},
							"apps_storage": {
								"type": "string",
								"description": "Path to the persistent storage for downloaded applications persistent storage top dir"
							},
							"apps_tmp": {
								"type": "string",
								"description": "Path to the temporary storage for applications being downloaded"
							}
						}
					}
				},
				"required": [
					"timeout",
					"storages"
				]
			}
		}
	}
}

{
	"$schema": "plugin.schema.json",
	"jsonrpc":"2.0",
	"info": {
		"title": "Local Inventory & Storage Manager of DAC Apps (LISA) Plugin",
        "class": "Lisa",
		"callsign": "org.rdk.dac.lisa",
		"locator": "libWPEFrameworkLisa.so",
		"status": "alpha",
		"autostart": true,
		"description": [
			"The Local Inventory & Storage Manager of DAC Apps (LISA) plugin allows authenticated downloading and management of DAC bundles from a remote server. It also manages the persistent storage of the DAC applications."
		],
		"version": "1.0"
	},
	"interface": {
		"$ref": "{interfacedir}/lisa.json"
	},
	"configuration": {
		"storages": {
			"apps": "/mnt/apps",
			"apps_storage": "/mnt/apps_storage",
			"apps_tmp": "/mnt/apps_tmp"
		},
		"network": {
			"timeout": 1800,
			"default_retryIn": 300
		}
	}
}

Development Phasing

Everything marked in italic is implemented so far

• Phase 1: basic API implementation and libs integration:
  • initialization with basic recovery on errors (removal of all data)
  • installation
    • libcurl HTTP get with HTTPS and TLS session resumption
    • HTTP code 202 back-off
    • persistent storage creation
    • untarring downloaded package
    • no authentication
    • no full metadata support (i.e. auxmetadata and resources)
    • handling of multiple versions of the same application
    • timeout is excluded
  • uninstall
    • full wipeout
  • operationStatus
    • basic status Success/Error
  • getStorageDetails
    • no params (overall) Request payload: {}
    • single installed application Request payload: {"type":"application/vnd.rdk-app.dac.native", "id":"<string>", "version":"<string>"}
  • getList:
    • no filters
    • single app  {"type":"application/vnd.rdk-app.dac.native", "id":"<string>", "version":"<string>"}
  • getMetadata
    • single app Request payload: {"type":"application/vnd.rdk-app.dac.native", "id":"<string>", "version":"<string>"}
  • getProgress
  • auth module API interface + stub library
  • Configure logical storages on all plaforms
  • Locking support (lock, unlock, getLockInfo) to prevent app from being removed while in use. LISA API Extension (Locking mechanism)
• Phase 2: whole API
  • full initialization with cleanup and maintenance added (already done)
  • cleanup and maintenance after each operation (already done for install and uninstall)
  •  installation
    • full metadata
    • configurable download timeout implementation
  • persistent storage management (full)
    • creation/deletion/reset
    • quota management and enforcing (TBD how and where)
    • usage reporting: per app, overall
  • download
  • reset
    • "storage"
    • "full"
    • "resources"
  • getStorageDetails
    • single installed application Request payload: {"type":"application/vnd.rdk-app.dac.native", "id":"<string>"}
  •  getList
    • filtering (already done)
  • setMetada (already done)
  • cancel (already done)
  • Configure quotas in AS/FSM
  • Review logical storages requirements
    • separately for all platforms
      
      • Phase 2: all supported platform
• review for all platforms: gaps
• Phase 3/later: 
  • TBD if needed: installation with authentication
    • at least API_KEY support
  • TBD: LGI authentication module
    • accessing CDNSharedSecret (check cat /mnt/secure_storage/cwmp/cwmp.xml | grep CDNSharedSecret)
  • TBD: apps.db - authentication, antirollback, encryption
  • TBD: concurrent parallel downloads

UI/resident app:

• reaction on quota exceeded

AWC/windows manager:

• installation flow
• upgrade flow